Quantum control on operations, exemplified by the quantum SWITCH, holds significant importance in quantum computing. To represent the quantum SWITCH in a program for general quantum channels, a language that permits measurements under quantum control is essential. A study of such a language can be found in Ying’s work. However, Ying’s work lacked argument on physical realization and left some insufficiently explained arbitrariness in the semantics.

In this extended abstract, we study a language that permits quantum controlled measurements from a different perspective. Our main idea is to delay and move out measurements in quantum conditional statements. Using this idea, we propose a program transformation, which provides a simple implementation and clarifies the origin of arbitrariness in Ying’s semantics. Furthermore, we extend our program transformation to quantum controlled recursion and discuss the implementability.